IN VITRO RESPONSES OF YUCCA SCHIDIGERA EXTRACT ON RUMINAL METHANE PRODUCTION, FERMENTATION CHARACTERISTICS AND DEGRADABILITY

Abstract

The present study was conducted in order to investigate the effects of Yucca Schidigera extract (YSE) at 25, 50 and 100 µl /75 ml culture ruminal fluid on in vitro ruminal fermentation characteristics, diet degradability and methane production using the semi-automatic system for gas production (GP) assay. Three rumen-cannulated Barki sheep (58.0 ± 2.3 kg of BW) were used as inoculum donors. The culture fluid was anaerobically incubated with 300 mg of a mixture of concentrate and peanuts hay (50:50, w/w) at 39oC for 24 h. Three runs of GP were used for each assay. Results showed that YSE addition to the diets decreased GP (P<0.05) than those obtained by the control. Compared with the control, CH4 production and NH3-N concentration were decreased by 37 and 18.5% with 25 µl YSE. Truly degraded dry matter (TDDM) was similar among the different levels of YSE addition. While truly degraded organic matter (TDOM) was decreased (P < 0.05) by 100 µl YSE addition but there were no differences among 25 and 50 µl levels of YSE addition. Ruminal acetate proportion was lower (P < 0.05) with 100 µl YSE compared with the control. Acetate to propionate ratio tended to decrease (P = 0.091) with the addition of YSE. Total rumen protozoal number increased (P< 0.05) by 50 µl YSE while decreased by 25 and 100 µl YSE addition. The results indicated that YSE exhibited a strong suppressing effect on ruminal methanogenesis, NH3-N concentrations and protozoal populations which could modify the rumen fermentation patterns may be a beneficial ruminal modifier for improving nutrient utilization and animal performance.